This invention relates to an excavator wear edge and, more particularly, to a replaceable assembly for protecting a leading edge or edges of a bucket or like earth engaging implement.
The invention finds utility in connection, for example, with the lip and/or wings of a dragline bucket, front end loader, face shovel, etc. In many instances the bucket may be equipped with transversely spaced excavating teeth to facilitate earth penetration. In the past, many operators have found it advantageous to protect both the bucket lip between teeth and the bucket wings as well. Exemplary of this is co-owned U.S. Pat. No. 3,621,594 marketed by ESCO Corporation of Portland, Oreg., U.S.A. under the trademark "ZIPPER LIP". Another type of lip wear edge can be seen in co-owned U.S. Pat. No. 3,865,177. Other patents dealing with lip wear edges are U.S. Pat. Nos. 3,995,384 and 4,748,754. Other protective shrouds can be seen in co-owned U.S. Pat. Nos. 3,171,500; 4,129,934 and 4,932,478.
The '384 patent shows a wear edge or bit for rearward slide mounting on a pair of trapezoidal mounting parts projecting upwardly from the lip, each mounting part having underbeveled sides with which the bit mates. A rearwardly-extending tongue hooks over a side-driven sandwich pin to prevent forward movement.
The '754 patent shows a wear edge or cap for pivot mounting on an L-shaped retaining piece projecting upwardly from the lip, the cap having a recess which hooks onto the retaining piece. The cap has an opening rearward of the retaining piece for receipt of a sandwich type lock.
Both of the prior art constructions fail to achieve the conflicting goals of wear parts in excavating equipment--to be reliably locked in place during operation yet being easily replaced when worn. In particular, the ever present shock loads prevent the realization of these contradictory goals. The combination of bearing surfaces and lock permits movement of the prior art wear edges which can result in disengagement of the wear edge and deterioration of the lock.
According to the invention, these disadvantages have been overcome through the provision of a generally U-shaped wear member having a T-shaped slot in one of the legs of the U-shape for rearward sliding engagement with a complementarily shaped boss on a face of the excavator and wherein the wear member is equipped with a transversely enlarged, keeper-equipped opening adjacent the rear end for the receipt of an essentially non-compressible lock which resists forward or disengaging movement and which is not subject to deterioration due to heavy, cyclic loadings.
Other advantages and objects of the invention may be seen in the details of the ensuing specification.